Well I good way to avoid little extra deductions is to make your routines shorter. Obviously, a floor routine cannot be shortened until you get new music. But on beam, try to make it short and to the point without going under the time limit. If you have extra skills that aren't requirements that you're likely to fall or get deducted for, take them out.
You may already be doing this, but I'd suggest while you're in practice to have your coach "score" you and be a pretend judge. My coach does this and it helps me get motivated to perfect my skills so when the time comes for my routine in the meet I'll be used to the feeling of having a judge there. Like you said, you're not freaked out. But you may be a little less concentrated knowing the judge is watching you.
And last but not least, although it may not be true, you may not completely understand how the scoring system works. How much different deductions are worth, etc... Like I said, might not be the case. But it's something to think about
Hope this helps!
